This invention relates to a multiple set, particularly an endless set with several single sheets or webs that are detachably glued together.
Multiple sets, particularly endless sets with two or more sheets or webs and, in some cases interposed carbon papers, are usually provided with a bonding in order to keep the sheets or webs together while being processed. This is particularly important for the processing of endless sets on computers.
The bonding may be done by various methods. Besides wire stitching are also known crimp-stitching, multiplex bonding (by means of paper-loops), Emerex-bonding (by means of an elastic thread), Fanlock-bonding (loop perforation), and finally the line glueing of sheet to sheet or web to web.
These known set connections do not always result in a good and sufficient securement and, moreoever, are sometimes very expensive and exhibit certain other disadvantages with the necessity of using a plurality of adhesive applying devices, the number depending on the sheet-number.
Wire stitching has the disadvantage that parts of the staples may break and thus lead to aggravating disturbances in the computing system. Crimp-bonding fulfills the requirement of keeping the sheets together but barely or even less when heavy sets are to be collated.
In Emerex-bonding the thread hanging out laterally interferes and makes processing prone to troubles. Fanlock-bonding also only rarely suffices when bonding large sets. Linear glueing between single sheets or webs frequently is accompanied by the danger that little knobs or protrusions occur in the glue lines which will prevent smooth running of the computer.
Another disadvantage of the present state of the art resides in the fact that the bonding of the sets frequently requires the use of extremely complicated and expensive special equipment.
Accordingly, it is an objective of the present invention to provide a multiple or endless set which ensures a practical detachable connection of single sheets or single webs that are glued together with a single adhesive applying device, and where the glueing together of single sheets or webs may be accomplished by the aid of a device that may be added on to each and every conventional collator. In order to achieve this objective, the present invention provides that the sheets or webs are, preferably excepting the last sheet and/or the cover sheet, provided at least at one lateral edge with recesses and that the sheets or webs are connected across these recesses by an adhesive coating.
In contradistinction to the heretofore used conventional glue connections where the edges of the web had to be furnished with a glue line, the present invention allows the simple glueing of the sheets or webs of a multiple set after the collating of the sheets or webs and, in some cases, of the carbon paper sheets or webs with a single adhesive applying device. The application of an adhesive in the area of the recesses of the sheets or webs assures a sufficient adhesive bond between all sheets or webs when the adhesive is preferably applied in the form of spots or strips at a distance from each other, covering the recesses of the sheets or webs at least in one direction.
The perforated margin or a second perforated margin may provide the recesses for making a later glueing of all sheets possible, in which case preferably the last sheet and/or first sheet is not perforated. Particularly advantageously, the adhesion-recesses are formed as additional recesses, in which case it is advantageous to provide for this purpose vertical or horizontal recesses. The transcending glueing of the sheets or webs assures a sufficient cohesion of the sheets or webs within the area of these perforations.
Another advantageous embodiment of the multiple set and particularly the endless set results when the width of the sheets or webs is chosen to differ, so that at least at one longitudinal edge, the end sheet or end web protrudes outwardly beyond the intermediate sheets or webs and that the top sheet or web is inwardly of the intermediate sheets or webs. This difference in the width of the sheets or webs does not reduce the useful area of the sheets or webs because this variation is only made in the margin which cannot be used. On the other hand, this variation of the width does not impair the collating and straightening out of single sheets or webs when the sets are put together because the common alignment is anyhow assured by the guide holes in the sheets or webs independently of the possible lateral stop of the edges of the sheets or webs.
The gradation of the width of the sheets or webs according to the invention allows a particularly simple manufacture, because it is not important for the application of the glue, preferably provided at spaced distances, that the glue be brought into coincidence with the glue recesses which would also be located at spaced distances. Due to the glue recesses caused by the varying width of the single sheets, the glue may be provided at arbitrary positions, as long as it is assured that their distances are smaller than half the length of a single set, so that at least two glueings occur along the edge of a page and thus a distortion free binding is obtained.
It is particularly advantageous when the sheets are different in their widths that their edges are arranged in a step-shape so that each sheet will be held in its marginal area by a glue strip and not only along its edge.
Obviously this step-shaped gradation of sheets or webs is suitable for weaker or lighter sets, because the margin of the sheets allows besides the guide perforation also such a gradation of 0.5 to 1 mm from sheet to sheet.
For stronger or heavier sets, the inner sheets or webs are of the same width or divided in two groups of different width. Experience has shown that a gradation of the upper and lower sheet or web against the inner sheet or web suffices in order to obtain a good bonding of the sheets or webs by applying strip glueings at certain distances from each other.
The embodiment of multiple, particularly endless sets according to the present invention, allows the use of particularly well working thermoplastic, so-called hotmelt adhesives which immediately after application is cooled to the extent that they set or congeal and thus immediately after application, yield the desired connection of the sheets or webs. Moreover, these hotmelt adhesives do not disturb the further processing of the sheets or webs because they are no longer sticky and are not capable of causing disturbing adhesion to parts of the machinery or on folded over or wound webs.
Besides the aforedescribed gradation of the sheets or webs, a further embodiment of the invention provides that the glue recesses, provided besides a Remalin-guide hole margin, are offset or differentially punched (for example, with holes of differing diameters) so that this method also leads to a scale-like overlapping and offset stepped array.
Another embodiment of the present invention provides for the omission of single recesses of the sheets or webs at certain positions, so that in various glue recesses, various sheets or webs are glued together.
It is particularly advantageous when the omitted glue recesses are arranged in such a manner, that for example some glue connections run from sheet 1 to 2, others from sheet 1 across sheet 2 to sheet 3, others again across sheet 1 to sheet 2 and sheet 3 and sheet 4. This practice not only leads to a particularly durable connection but also an advantageous variable group division which is particularly useful for sets of forms, where each time several sheets form a subgroup which has to be treated individually.
This latter particularly useful embodiment results, for example from leaving out in the second sheet one recess when starting at a top sheet with its recesses provided at regular distances. In the third sheet, for example one recess left and one right of the respective recess in the second sheet is omitted and so on down to the bottom, so that recesses are missing on each sheet at certain positions.
Moreover, in a further embodiment recesses may be left out in the cover sheet and in the bottom sheet and only the intermediate sheets may be furnished wth variably arranged recesses in order to obtain the same heretofore described result of glueing the whole set by applying the adhesive either to the front side of the top sheet or the back side of the bottom sheet.
A further embodiment of the invention provides that the glue recesses, which are provided in addition to the customary guide hole margins, are offset relative to the holes vicinally of the guide hole margins. This method leads to a minimum loss of useful width of sheets or webs, while there is still enough material between the guide holes and the glue recesses to prevent tearing of the paper.
The embodiment according to the invention is particularly useful for sets with intercalated carbon paper sheets or webs in which case the carbon paper sheets or webs are provided with exactly the same recesses as the appropriate sheet of the set so that it belongs in each case to the same subgroup of the set.
Similarly the carbon paper sheets may partly project into the recesses of the sheets or webs of the set and may also be connected to the whole set by glueing without providing separate recesses for the carbon paper sheets or webs.
For the manufacture of multiple sets and particularly endless sets according to the present invention a rotary die cutting tool is used which is fixed on the rotary printing press with dies or die rings which are adjustable both in the direction of running and in the opposit direction. In this case the dies and the sleeves of the rings are exchangeable also so that they may be exchanged against smaller or larger dies in order to achieve by this method the aforementioned embodiment of graded edges due to variously size recesses in each web. Such exchanges provide as well for translation of the whole tool in longitudinal as well as in vertical directions.
Furthermore, it may be provided that the glue recesses and the printing are not manufactured simultaneously on a printing press but that the recesses are punched on a special die tool which has been provided additionally to the collator after the whole set has been collated. In this case the sets, as the case may be, together with the intercalated carbon paper and all other sheets and webs will be provided with recesses. All webs, sheets and carbon papers are glued together taking care that a glue repellant, Teflon-coated roller runs over the cover sheet and over the bottom sheet. According to the technique of printing (print face-up, roll-winding with pressure outwards, or print face-down and roll-winding with pressure inwards) the first or the last sheet or both may be devoid of recesses or die cuts. For this purpose the die cutting device, provided upon the automatic collator will be offset by one collating station so that the die cuts for example extend on a sextuple set only over sheets 1 to 5 or according to the printing technique only over sheets 2 to 6 or 2 to 5. The application of the glue occurs in the first case on the face of the last sheet and in the second case on the back of the cover sheet, each time glue repellant counter-pressure rollers being provided.
When using carbon paper the difficulty arises of registering the recesses therein with the recesses of the overlying and underlying papers because the large tension might cause wandering of the glue recesses. On the other hand the use of "color reaction paper" prevents a smooth and permanent bond because none of the existing brands of glue allows sufficient adhesion of the glue to the side of a sheet which is coated with a micro encapsulated chemical.
In order to remove these difficulties another embodiment of the present invention provides that the sheets or webs of carbon paper or other sheets or webs which are not provided with glue hole margins, are in such a way provided with recesses that in a longitudinal direction, the width of the bridges between the recesses is smaller or at least identical with the hole width of the glue recesses of the sheets lying either above or below.
This embodiment makes it in any case sure, similar to the aforedescribed embodiment of the carbon sheets in such a manner that they protrude only partly in the glue recesses of the above and below lying paper, that independently of the longitudinal order of the carbon paper sheets in relation to the neighboring sheets there exists one transversal recess allowing the passing through of the glue. Thus there is no chance that an unfavorable longitudinal offset distribution of the glue recesses of the carbon paper could cover completely the bridges between the glue recesses of the vicinal sheet.
When using color reaction paper the first sheet or web should consist according to the invention of ordinary paper and the second sheet or web should be self-reacting on its face and reacting or donating on its backside. The consecutive sheets are CFB in other words the front side is accepting and the backside is coated with donor microcapsules. The bottom sheet is frontally accepting (CF).
When one of the intercalated sheets or webs is chosen as a carrier for the glue in such a manner that the glue is applied to both sides of this intercalated sheet, this sheet should be acceptor-coated on its frontal side, while the underneath lying sheet or web is self-reactive on its front side and coated with capsules on its backside. When color reaction paper is used, even when chosing an intercalated sheet as a glue carrier, the first sheet must be an ordinary paper in order to prevent a coating of capsules on its backside, which would prevent a good bond.
The device for the manufacture of multiple sets or endless sets according to the invention may as a further embodiment be provided with a pressure device in tandem with the glueing station, that is a pressure roller in order to assure a satisfactory distribution of the glue.
Moreover, it is also within the scope of the present invention to furnish the device for the manufacture of multiple sets or endless sets according to the invention with a blower combined with a heating or cooling device in order to shorten the so-called "open-time" of the glue. When cold glue is used, heating may considerably shorten the open time, in other words the time where a bond has not yet occurred which might prevent slippage. The same applies to cooling when a hot glue is used. Heating or cooling may occur, as desired, either from above or below.
Other features which are considered characteristic of the invention are set forth in the appended claims.
Although the invention is illustrated and described in relationship to specific embodiments, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The constructions and operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of the specific embodiments when read in connection with the accompanying drawings.